Tremolo device for electric self-playing violins



B. E. MILLS.

TREMOLO DEVICE FOR ELECTRIC SELF PLAYING VlOLlNS.

AFPLlCATlGH FILED JULY H. 1921.

1 ,407,434, Patented Feb. 21, 1922.

2 SHEETS-SHEET I B. E. MlLLS. TREMOLO DEVICE FOR ELECTRIC SELF PLAYING VIOLINS.

APPLICATION FILED JULY 11, 1921.

1 ,4;O7,434;, Patented Feb. 21, 1922.

2 SHEETS-SHEET Z- UNITED STATES BERTIE E. MILLS, OF CHICAGO, ILLINOIS,

ASSIGNCR TO MILLS NOVELTY CO1YI?ANY,

OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TREMOLO DEVICE FOR- ELECTRIC SELF-PLAYING VIOLINS.

Application filed July 11, 1921.

T all whom it man concern:

Be it known that I, BERTIE E, MrLLs, a citizen of the United States, residing at Jackson Boulevard and Green Street, Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Tremolo Devices for Electric Self-Playing Violins, of which the following is a specification.

My invention relates more particularly to an improvement in that feature of the selfplaying violin of United States Letters Patent to Henry K. Sandell, No. 855,021, which serves for producing the tremolo or vibrato eifect of human violin-playing.

The more important objects of my present improvement are to enhance the sensitiveness of the mechanism for the stated purpose and: to enable the force of the vibrato effect to be regulated.

Referring to the accompanying drawings, Figure 1 is abroken plan view of an electric self-playing violin of the type exemplified in the aforesaid patent, with my improvement embodied therein and showing enough of the instrument and its operating parts to enable the operation of the improved feature to be readily understood; and Figure 2 is a broken section on line 22, Fig. 1.

The violin 3 is played by the sounders 4, 4, or bows, on rotary shafts 5, 5,. one for each string 6, and driven by an electric motor 7 having its shaft suitably geared to the shafts 5, the gearing being enclosed in a housing 8. The shafts are operated to maintain the sounders normally raised off the strings, by levers 9 connected between their ends with a rock-shaft 10 journaled in suitable bearings, the levers being spaced apart by collars 11 and carrying at their rear ends, armatures 12 provided to be worked by electromagnets 13 for rocking the levers to apply theconstantly rotating sounders to the violin-strings while they are being fingered by. mechanism, of which a portion is indicated at 14 in Fig. 1, for playing one string.

The tail-piece 15, which is shown in Fig. 1 to be connected at its forward end by strings 16, 16 with the bridge 17 is vibrated substantially as and for the purpose explained in the aforesaid patent by my improved mechanism for the purpose, which is described as follows:

Specification of Letters Patent.

Patented Feb. 21, 1922.

Serial No. 483,936.

The rod 18, connected at one end with the tail-piece, passes at its opposite, threaded end through the upper end of the pendulous lever 19, fulcrumed at 20 and with which the rod is adjustably connected by the thumb-nuts shown thereon to bear against the opposite faces of the lever. The lower part of the pendulous lever is bent into the recess-form shown, and the end below the iecess alines with the straight lever-section above the recess and carries adjustably a horizontally extending weight 21 having adjustably fastened on its advance-end a projecting headed push-stem 22. In the leverrecess is provided an armature 23 opposed to the poles of an electromagnet 24 which is suspended on the lower-end portion of a metai plate 25 secured to depend from the portion of the frame 26 on which the lever 19 is 'i'ulcrumed, as shown, and through a relatively wide opening 2'? in which an opening 27 in the partition '28 the swinging lever passes. A block 29 of insulating material is secured on the lower part of the plate 25 and has a metallic lever 80 fulcrumed upon it at 30 between the leverends. A spring 31 bears outwardly against the upper part of the lever 30, the lower end of which is opposed to the push-stem 22; and this lever carries on its inner face, at 32, a circuit-closing spring contact. The electromagnet is included in the circuit of an electric generator, conventionally indicated at 33, one side of which is connected by a conducting wire 34 with a binding-post on the lever 30. From the other side of the generator extends the wire 35 to a pivoted switch-lever 36 applicable to either of two contacts 36 and 36 and simultaneously to both. A branch 35 of the circuit connects the Contact 36 with the outer windings a: of the spools 24, from which it leads to a binding-post 37 another branch, 35" connects the contact 36 ,with the inner windings y of the spools (those nearest the magnet-cores) and leads to the same binding-post.

By applying the switch-lever 36 to either cont-act, the electromagnet is energized comparatively mildly, and more forcibly when applied to the contact 36", to attract the armature and swing the lever to impel the tailpiece in one direction, by which movement of the lever the stem 22 pushes against the lever 30 to separate the spring-contact 32 from the terminal of the binding-post 37 and break the circuit, thereby deenergizing the electromagnet and compressing the spring 31. With the electromagnet deenergizechthe weight 21 swings the lever 19 backward to impel the tail-piece in the opposite direction, whereupon the recoil ot' the spring 31 turns the lever 30 to apply the contact to the terminal 37 and again energize the electromagnet. These successive movements of the lever 19 are rapidly repeated so long as the switch remains closed at a contact 36* or 36*, with the result of shaking the tail-piece with greater or less force, depending on the particular contact engaged by the switch-lever 3G; and the resultant vibration of the violinstrings varies the pitch or each string being played by a sounder 4 to produce the desired vibrato eifect. To enhance to the utmost the force of the vibratory action of the tail-piece, the elongated contact-end oi? the lever 36 is caused to bridge the contacts 36 and 36", thereby including both the inner and outer electromagnet-windings in the circuit and accordingly increasing the magnetic power.

I realize that considerable variation is possible in the details of the construction of my improved device herein shown, and I do not intend to limit my invention thereto except as pointed out in the appended claims, in which it is my intention to claim all the novelty inherent in my invention as broadly is permissible by the state oi the art.

I claim:

1. In combination with a stringed instrument, a pendulous vibratory lever connected with the strings of the instrument, and electrio means for vibrating said lever, comprising an electromagnet in an electric circuit including a switch having contact-memhers respectively connected with the inner and outer electromagnet-windings and a lever-member operative to close the circuit at either contact to energize the electromagnet for regulatin the force of said levers vibrations.

2. In con'ibination with the tail-piece of a stringed instrument, a pendulous vibratory weighted lever connected with the tail-piece and carrying an armaturev an electri'imagnet in an electric circuit, and a lever fulcrumed between its ends adjacent the electromagnet, spring-pressed at one side oi its fulcrum and carrying an electric contact at the opposite side thereof to engage a terminal in said circuit and extend into the path oi the weight on the lever.

3. In combination with the tail-piece of a stringed instrument, a pendulous vibratory bent lever connected with the tail-piece and carrying an armature and a weight having apush-stem adjustably projecting from the weight, an electromagnet in an electric circuit, and a lever fulcrumeil between its ends adjacent the electromagnet, spring-pressed at one side of its fulcrum and carrying an electric contact at the opposite side thereof to engage a terminal in said circuit and extending into the path of said push-stem.

4. In combination with the tail-piece of a stringed instrument, a pendulous vibratory weighted lever connected with the tailpiece and carrying an armature, an electromagnet in an electric circuit containing a switch having a pair of contacts for separate and simultaneous engagement by the switchlever, one of said contacts being included in a branch of the circuit leading through the outer windings of the electromagnet-spools to a binding-post and the other contact being included in another branch of the circuit leading through the inner windii'igs of said spools to said bindingpost, and a lever fulcrumed between its ends adjacent the electromagnet, spring-pressed at one side of its fulcrum and carrying an electric contact at the opposite side thereof to engage a terminal on said binding-post and extend into the path of said weight.

BERTIE E. M ILLS, 

